The present invention relates to a texturizing device for a yarn conditioning plant. This device comprises a pair of feed rollers for feeding at least one yarn to be crimped; a stuffer box that crimps the yarn, said stuffer box having a stuffer box channel, a channel inlet opening, and a channel outlet opening; and a conveyor for transporting the crimped yarn to a heat setting chamber.
Known texturizing devices of this kind (German published patent application 4,243,765) are used to stuff yarn mechanically in such a way that the yarn becomes crimped. The stuffing takes place in a stuffer box by exerting a retarding force on the continuously fed-in yarn, whereby the yarn is laid down in random loops in the stuffer box channel and accumulates. The accumulated yarn layers are gradually pushed out through the exit end of the stuffer box by the continuously fed-in yarn. The crimping of the yarn should be maintained after leaving the stuffer box for subsequent treatment. For this reason, the crimped yarn is fed by a transporting device continuously into a heat setting chamber, whereby the crimping is heat set. The crimped yarn is then used in the form of so-called frieze yarn for the production of various end products, such as carpets.
The practically used stuffer box comprising the known stuffer box channel is made from a plurality of housing parts. The cross section of the known stuffer box channel is rectangular. Single fibers or filaments might accumulate at the parting lines, and thus impair the crimping process. A similar shortcoming arises at the edges of the cross section.
An object of the present invention is to provide a stuffer box comprising a stuffer box channel which is operationally reliable.
This object has been achieved-in accordance with the present invention by applying a stuffer box channel which has a closed circular cross section free from any parting lines.
The novel stuffer box is made from one piece thus avoiding any parting lines. Because of the predominantly constant and circular cross section, there are no impairments based on any discontinuity surfaces.
In a preferable embodiment, the stuffer box channel is continuously cylindrical. If necessary, the stuffer box channel may be provided with a taper in the area of its outlet opening; thus a certain retarding force is effective so that the crimped yarn cannot lose its crimping. This retarding force may preferably be increased by providing a pivotable lid in the area of the outlet opening. The retarding force is effective against the movement of the yarn; it might be caused either by the weight of the lid itself or by an additional spring force.
In a further embodiment of the present invention the stuffer box comprises at least one air inlet opening, which leads into the stuffer box channel, and which is directed against the channel inlet opening. Thus a crimping effect is attained when the production is started. The air stream serves as a brake force thus causing the yarn to form a hank. As soon as this hank is formed, the air stream can be stopped. The hank does not disentangle although the conveyor continuously withdraws, and the feed rollers continuously feed the yarn.
The reliability in operation can be additionally increased by providing the stuffer box channel with a sealing projection which projects into the wedge-shaped contour of the feed rollers.
A delivery device might be arranged between the stuffer box and the conveyor which device is, for example, a chute. It is also possible to attach a hinged forwarding channel to the exit of the stuffer box.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.